Hydraulic pressure supply system of dual clutch transmission for vehicle

ABSTRACT

Disclosed is a hydraulic pressure supply system of a dual clutch transmission for a vehicle in which by independently configuring a low pressure supply route and a high pressure supply route, the hydraulic pressure supply system can enable a low hydraulic pressure that is generated in a hydraulic pump for a low pressure to be supplied to a gear lubrication device and a clutch cooling/lubrication device and enable a low hydraulic pressure that is generated in a hydraulic pump for a high pressure to be supplied to a gear control device and a clutch control device.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No.10-2016-0091984 filed on Jul. 20, 2016, the entire contents of which isincorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a hydraulic pressure supply system of adual clutch transmission for a vehicle. More particularly, the presentinvention relates to a hydraulic pressure supply system of a dual clutchtransmission for a vehicle that independently supplies each of hydraulicpressures that are supplied to a lubrication device of a gear and clutchrequiring much flow rate and a control device of a gear and clutchrequiring a hydraulic pressure of a high pressure.

Description of Related Art

Environmentally-friendly technology of a vehicle is core technology of afuture vehicle industry, and vehicle makers devote their strength todevelopment of an environmentally-friendly vehicle for satisfyingenvironment and fuel consumption regulations.

The future vehicle technology exemplifies an Electric Vehicle (EV) and aHybrid Electric Vehicle (HEV) using electrical energy and a DoubleClutch Transmission (DCT) having improved efficiency and convenience.

The DCT has two clutch devices within an automatic transmission and agear train of a manual transmission. The DCT selectively transmits atorque that is input from an engine to two input shafts using twoclutches and shifts and outputs a torque that is selectively transmittedto the two input shafts using the gear train.

The DCT attempts to compactly implement a transmission that implements ahigh gear shift stage of a five-speed or more and controls two clutchesand a synchronizing device by a controller, thereby being implementedinto an Auto Manual Transmission (AMT) that makes a driver's manualshift unnecessarily.

Accordingly, compared with an automatic transmission using a planetarygear set, the DCT has excellent power delivery efficiency and easilyperforms a change and addition of a component for implementing amultistage and thus can cope with a fuel consumption regulation andimprove multistage efficiency.

In the DCT, because a lubrication device and a control device requiredifferent hydraulic pressures and flow rates, it is necessary toindependently supply a hydraulic pressure to the lubrication device andthe control device.

The information disclosed in this Background of the Invention section isonly for enhancement of understanding of the general background of theinvention and should not be taken as an acknowledgement or any form ofsuggestion that this information forms the prior art already known to aperson skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing ahydraulic pressure supply system of a dual clutch transmission for avehicle having advantages of being configured for independentlysupplying each of hydraulic pressures that are supplied to a lubricationdevice of a gear and clutch requiring much flow rate and a controldevice of a gear and clutch requiring a hydraulic pressure of a highpressure (i.e., a pressure higher than a predetermined pressure).

Various aspects of the present invention are directed to providing ahydraulic pressure supply system of a dual clutch transmission for avehicle including: a low pressure supply route including a low pressuresupply route comprising a low pressure hydraulic pump that generates alow hydraulic pressure using a fluid that is stored at a low pressureoil pan and that supplies the generated low hydraulic pressure directlyto a gear lubrication device and a clutch cooling/lubrication device,and a cooler that cools a portion of a low hydraulic pressure that issupplied from the low pressure hydraulic pump and that supplies theportion of the low hydraulic pressure to the gear lubrication device orthe clutch cooling/lubrication device; and a high pressure supply routeincluding a high pressure hydraulic pump that generates a hydraulicpressure of a high pressure using a fluid that is stored at a highpressure oil pan and that supplies the generated high hydraulicpressure, a clutch control device including first and second clutchpressure control solenoid valves that supply a portion of the hydraulicpressure of a high pressure (i.e., a pressure higher than apredetermined pressure) to first and second clutches, and a gear controldevice including a gear actuator pressure control solenoid valve that isconfigured to control other portions of the hydraulic pressure of a highpressure and that supplies the controlled hydraulic pressure to a gearactuator, wherein the low pressure supply route and the high pressuresupply route each are formed with an independent closed circuit.

The gear control device may further include a gear actuator flow ratecontrol solenoid valve that is positioned between the gear actuatorpressure control solenoid valve and the gear actuator and that regulatesa flow rate of a hydraulic pressure that is supplied from the gearactuator pressure control solenoid valve to supply the flow rate to thegear actuator.

The low pressure supply route may further include a low pressure filterthat is disposed between the low pressure oil pan and the low pressurehydraulic pump.

The low pressure supply route may further include a clutch protectionrelief valve and a first orifice that are disposed between upstream anddownstream of the cooler.

The clutch protection relief valve may be formed with a one-way valvethat supplies a hydraulic pressure only from the upstream side to thedownstream side of the cooler.

The low pressure supply route may further include a switching valveregulating a flow rate supplied from the low pressure hydraulic pump andsupplying the regulated flow rate selectively to the gear lubricationdevice and the clutch cooling/lubrication device.

The low pressure supply route may further include an ejection flowchannel that is formed between the low pressure hydraulic pump and theswitching valve, a first distribution flow channel that detours theswitching valve and connects the low pressure hydraulic pump with thegear lubrication device, a second distribution flow channel that detoursthe switching valve and connects the low pressure hydraulic pump withthe clutch cooling/lubrication device, a first bypass flow channel thatis formed between the switching valve and the gear lubrication device,and a second bypass flow channel that is formed between the switchingvalve and the clutch cooling/lubrication device.

The low pressure supply route may further include a branch flow channelthat connects the ejection flow channel and the first distribution flowchannel, and the cooler may be disposed on the branch flow channel.

The low pressure supply route may further include a second orifice thatis positioned on the first bypass flow channel between the cooler andthe gear lubrication device and a third orifice that is positioned onthe second distribution flow channel.

The high pressure supply route may further include a first high pressurefilter that is positioned at the upstream side of the high pressurehydraulic pump, a second high pressure filter that is disposed at thedownstream side of the high pressure hydraulic pump, and an one-wayvalve that is disposed in series to the second high pressure filter atthe downstream side of the high pressure hydraulic pump.

The first high pressure filter may be formed with a mesh filter, and thesecond filter may be formed with a pressure filter.

The clutch control device may further include a fail-safe solenoid valvethat is positioned at the upstream side of the first and second clutchpressure control solenoid valves.

The high pressure supply route may further include a supply flow channelthat connects the high pressure hydraulic pump, the clutch controldevice, and the gear control device, and at the supply flow channel, anaccumulator that temporarily stores hydraulic pressure supplied from thehigh pressure hydraulic pump and supplies the stored hydraulic pressureto the clutch control device, a line relief valve that maintains ahydraulic pressure on the supply flow channel to a predeterminedpressure or less, and a pressure sensor that detects a hydraulicpressure on the supply flow channel are positioned.

According to an exemplary embodiment of the present invention, byindependently configuring a low pressure supply route and a highpressure supply route, a low hydraulic pressure that is generated in ahydraulic pump for a low pressure can be supplied to a gear lubricationdevice and a clutch cooling/lubrication device, and a low hydraulicpressure that is generated in a hydraulic pump for a high pressure canbe supplied to a gear control device and a clutch control device.

Accordingly, as the gear control device and the clutch control deviceare formed with an independent closed circuit, cleanliness of solenoidvalves can be maintained. Further, by using a clutch lubricant, which isan exothermic element together with a gear lubricant, a churning losscan be minimized.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from or are set forth in moredetail in the accompanying drawings, which are incorporated herein, andthe following Detailed Description, which together serve to explaincertain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a hydraulic pressure supply systemaccording to exemplary embodiments of the present invention.

FIG. 2 is a hydraulic pressure system diagram of a low pressure supplyroute that is applied to a hydraulic pressure supply system according tothe first exemplary embodiment of the present invention.

FIG. 3 is a hydraulic pressure system diagram of a high pressure supplyroute that is applied to a hydraulic pressure supply system according tothe first exemplary embodiment of the present invention.

FIG. 4 is a hydraulic pressure system diagram of a low pressure supplyroute that is applied to a hydraulic pressure supply system according tothe second exemplary embodiment of the present invention.

FIG. 5 is a hydraulic pressure system diagram of a high pressure supplyroute that is applied to a hydraulic pressure supply system according tothe second exemplary embodiment of the present invention.

It should be understood that the appended drawings are not necessarilyto scale, presenting a somewhat simplified representation of variousfeatures illustrative of the basic principles of the invention. Thespecific design features of the present invention as disclosed herein,including, for example, specific dimensions, orientations, locations,and shapes will be determined in part by the particular intendedapplication and use environment.

In the figures, reference numbers refer to the same or equivalent partsof the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of thepresent invention(s), examples of which are illustrated in theaccompanying drawings and described below. While the invention(s) willbe described in conjunction with exemplary embodiments, it will beunderstood that the present description is not intended to limit theinvention(s) to those exemplary embodiments. On the contrary, theinvention(s) may be intended to cover not only the exemplaryembodiments, but also various alternatives, modifications, equivalentsand other embodiments, which may be included within the spirit and scopeof the invention as defined by the appended claims.

The drawings and description are to be regarded as illustrative innature and not restrictive. Like reference numerals designate likeelements throughout the specification.

In the following description, dividing names of components into first,second and the like is to divide the names because the names of thecomponents are the same as each other and an order thereof is notparticularly limited.

FIG. 1 is a schematic view of a hydraulic pressure supply systemaccording to exemplary embodiments of the present invention.

The hydraulic pressure supply system of FIG. 1 may be used for a DualClutch Transmission (DCT). In the DCT, a plurality of input gears aredistributed and positioned at two input shafts, and a plurality ofoutput gears that are gear engaged with the plurality of input gears aredistributed and positioned at two output shafts. Further, the DCTincludes a plurality of synchronizer mechanisms, and the plurality ofsynchronizer mechanisms selectively operate to connect one of theplurality of output gears and one of the two output shafts. Further, theDCT includes first and second clutches C1 and C2 (see FIG. 3), and thefirst and second clutches C1 and C2 each transfer power of a powersource (e.g., engine or motor) to one of the two input shafts. The firstand second clutches C1 and C2 alternately operate.

Referring to FIG. 1, in a hydraulic pressure supply system according toan exemplary embodiment of the present invention, a low pressure supplyroute LS and a high pressure supply route HS are independentlyconfigured.

The low pressure supply route LS is configured to supply a low hydraulicpressure that is generated in a low pressure hydraulic pump EOP1 to agear lubrication device GL and a clutch cooling/lubrication device CCL,and a high pressure supply route HS is configured to supply a highhydraulic pressure that is generated in a high pressure hydraulic pumpEOP2 to a gear control device GC and a clutch control device CC.

The low hydraulic pressure means a hydraulic pressure that is configuredto be controlled and supplied with a lower pressure of a level thatenables to smoothly perform cooling and lubrication of a shift gear thatis related to a shift and a clutch that controls power of an engine, anda high hydraulic pressure means a hydraulic pressure that smoothlyoperates a clutch that is configured to control power of an engine andthat is configured to be controlled and supplied with a high pressure(i.e., a pressure higher than a predetermined pressure) of a level thatmay operate a synchronizer mechanism for a shift. Further, a flow rateof a low hydraulic pressure is relatively larger than that of a highhydraulic pressure.

FIG. 2 is a hydraulic pressure system diagram of a low pressure supplyroute that is applied to a hydraulic pressure supply system according tothe first exemplary embodiment of the present invention.

Referring to FIG. 2, a low pressure supply route LS includes a lowpressure hydraulic pump EOP1. The low pressure hydraulic pump EOP1generates a low pressure using oil that is input from a low pressure oilpan OP1 through a low pressure filter LF and supplies the generated lowpressure to an ejection flow channel 2. The low pressure is supplied toa gear lubrication device GL and a clutch cooling/lubrication device CCLthrough first and second distribution flow channels 4 and 6 connected tothe ejection flow channel 2.

Further, a cooler CL and a clutch protection relief valve CRV arepositioned in parallel between a branch flow channel 8 that is branchedat the upstream side of the ejection flow channel 2 and any onedistribution flow channel 4 of the first and second distribution flowchannels 4 and 6.

The clutch protection relief valve CRV is positioned to supply oil inone direction from the branch flow channel 8 to the first distributionflow channel 4.

Further, a first orifice OR1 is positioned on the ejection flow channel2 between the first and second distribution flow channels 4 and 6 andthe branch flow channel 8 to enable to always supply a portion of oilthat is supplied from the low pressure hydraulic pump EOP1 to the branchflow channel 8. Therefore, the first orifice OR1 enables oil to alwayssupply to the cooler CL.

Further, second and third orifices OR2 and OR3 are positioned on thefirst and second distribution flow channels 4 and 6. When a hydraulicpressure that is supplied from the low pressure hydraulic pump EOP1 issupplied to the gear lubrication device GL and the clutchcooling/lubrication device CCL through the first and second distributionflow channels 4 and 6, the second and third orifices OR2 and OR3 mayenable the hydraulic pressure to be stably supplied.

Wet DCT exclusive oil may be used as oil using for a low pressure supplyroute LS, and it is preferable that a non-woven fabric type filter isused as a low pressure filter LF.

FIG. 3 is a hydraulic pressure system diagram of a high pressure supplyroute that is applied to a hydraulic pressure supply system according tothe first exemplary embodiment of the present invention.

Referring to FIG. 3, a high pressure supply route HS includes a highpressure hydraulic pump EOP2. The high pressure hydraulic pump EOP2generates a high pressure using oil that is injected from a highpressure oil pan OP2 through a first high pressure filter HF1. Thegenerated high pressure passes through a second high pressure filter HF2and a one-way valve OV and is supplied to the clutch control device CCand the gear control device GC through a supply flow channel 14.

Further, an accumulator ACC, a line relief valve RRV, and a firstpressure sensor PS1 are positioned on the supply flow channel 14.

The accumulator ACC for a predetermined time stores a hydraulic pressurethat is supplied from the high pressure hydraulic pump EOP2 and suppliesthe stored hydraulic pressure to the supply flow channel 14, as needed.

The line relief valve RRV maintains a hydraulic pressure on the supplyflow channel 14 to a predetermined pressure or less, and the pressuresensor PS detects a pressure on the supply flow channel 14 and transfersa signal thereof to a transmission control device.

The clutch control device CC includes first and second clutch pressurecontrol solenoid valves CP-SOL1 and CP-SOL2. A hydraulic pressure thatis supplied from the supply flow channel 14 is supplied to the first andsecond clutch pressure control solenoid valves CP-SOL1 and CP-SOL2.

The first and second clutch pressure control solenoid valves CP-SOL1 andCP-SOL2 control the hydraulic pressure to selectively supply thehydraulic pressure to the first and second clutches C1 and C2.Accordingly, the first and second clutches C1 and C2 alternatelyoperate.

It is exemplified but is not limited that the clutch control device CCcontrols two clutches C1 and C2. If the first exemplary embodiment isapplied to a hybrid electric vehicle, one clutch serving as an engineclutch may be added and the one clutch may be disposed in parallel withthe two clutches C1 and C2.

The gear control device GC includes a gear actuator pressure controlsolenoid valve GAP-SOL and a gear actuator flow rate control solenoidvalve GAL-SOL. A hydraulic pressure that is supplied from the supplyflow channel 14 is configured to be controlled in the gear actuatorpressure control solenoid valve GAP-SOL and is supplied to the gearactuator flow rate control solenoid valve GAL-SOL.

Thereafter, the gear actuator flow rate control solenoid valve GAL-SOLregulates a flow rate of the hydraulic pressure to supply the flow rateto any one chamber of two chambers of a gear actuator ACT thatmanipulates a synchronizer mechanism and returns a hydraulic pressurewithin another chamber.

The number of the gear actuator flow rate control solenoid valve GAL-SOLand the gear actuator ACT is determined according to the number of agear shift stage in which the DCT implements, and the gear actuator ACTand the gear actuator flow rate control solenoid valve GAL-SOL of oneset may control two gear shift stages.

It is preferable that the first high pressure filter HF1 that is appliedto the high pressure supply route HS is formed with a mesh filter andthat the second high pressure filter HF2 is formed with a pressurefilter, and it is preferable that oil is low viscosity exclusive oil forthe control.

Further, by applying the high pressure hydraulic pump EOP2 and theaccumulator ACC, when a hydraulic pressure is a predetermined pressureor less (approximately 40 bar), the high pressure hydraulic pump EOP2operates to supply an operation pressure to the accumulator ACC and thesolenoid valves, and when the hydraulic pressure is a predeterminedpressure or more (approximately 60 bar), the high pressure supply routeHS stops operation of the high pressure hydraulic pump EOP2 and suppliesa hydraulic pressure that is stored at the accumulator ACC to solenoidvalves.

The low pressure hydraulic pump EOP1 and the high pressure hydraulicpump EOP2 are configured with an electric motion type hydraulic pumpthat is independently driven by motors M1 and M2, respectively.

FIG. 4 is a hydraulic pressure system diagram of a low pressure supplyroute that is applied to a hydraulic pressure supply system according tothe second exemplary embodiment of the present invention.

Referring to FIG. 4, the low pressure supply route LS according to thesecond exemplary embodiment of the present invention, compared with thefirst exemplary embodiment, further includes a switching valve SWV. Theswitching valve SWV regulates a flow rate by the control of a magnet MGand supplies the regulated flow rate to the gear lubrication device GLand the clutch cooling/lubrication device CCL through first and secondbypass flow channels 10 and 12.

Downstream portions of the first and second bypass flow channels 10 and12 are connected to downstream portions of the first and seconddistribution flow channels 4 and 6, especially to downstream portions ofthe second and third orifices OR2 and OR3.

Therefore, the low pressure supply route LS according to the secondexemplary embodiment of the present invention can stably supply thehydraulic pressure supplied from the low pressure hydraulic pump EOP1 tothe gear lubrication device GL and the clutch cooling/lubrication deviceCCL through the second and third orifice OR2 and OR3 positioned on thefirst and second distribution flow channels 4 and 6.

In addition, hydraulic pressure may be supplied selectively any one ofthe gear lubrication device GL and the clutch cooling/lubrication deviceCCL by the switching valve SWV controlled by the magnet MG.

FIG. 5 is a hydraulic pressure system diagram of a high pressure supplyroute that is applied to a hydraulic pressure supply system according tothe second exemplary embodiment of the present invention.

Referring to FIG. 5, the high pressure supply route HS according to thesecond exemplary embodiment of the present invention, compared to thefirst exemplary embodiment, further includes a fail-safe solenoid valveFS-SOL.

The fail-safe solenoid valve FS-SOL is positioned on the supply flowchannel 14 upstream of the first and second clutch pressure controlsolenoid valves CP-SOL1 and CP-SOL2, and supplies hydraulic pressure toany one clutch of the first and second clutches C1 and C2 even when thehydraulic pressure supply system is out of order.

In a hydraulic pressure supply system for a DCT according to anexemplary embodiment of the present invention, a low pressure supplyroute LS and a high pressure supply route HS are independentlyconfigured, and the hydraulic pressure supply system enables a lowhydraulic pressure that is generated in a low pressure hydraulic pumpEOP1 to be supplied to a gear lubrication device GL and a clutchcooling/lubrication device CCL and enables a low hydraulic pressure thatis generated in a high pressure hydraulic pump EOP2 to be supplied to agear control device GC and a clutch control device CC.

Accordingly, as the gear control device and the clutch control deviceeach are formed with an independent closed circuit, the gear controldevice and the clutch control device may maintain cleanliness ofsolenoid valves. Further, by using a clutch lubricant, which is anexothermic element together with a gear lubricant, a churning loss canbe minimized.

For convenience in explanation and accurate definition in the appendedclaims, the terms “upper”, “lower”, “inner” and “outer”, “up,” “down,”“upper”, “lower,” “upwards,” “downwards”, “front”, “rear”, “back”,“inside”, “outside”, “inwardly,” “outwardly,” “interior”, “exterior”,“inner,” “outer”, “forwards” and “backwards” are used to describefeatures of the exemplary embodiments with reference to the positions ofsuch features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of thepresent invention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described in orderto explain certain principles of the invention and their practicalapplication, to thereby enable others skilled in the art to make andutilize various exemplary embodiments of the present invention, as wellas various alternatives and modifications thereof. It is intended thatthe scope of the invention be defined by the Claims appended hereto andtheir equivalents.

What is claimed is:
 1. A hydraulic pressure supply system of a dualclutch transmission for a vehicle, the hydraulic pressure supply systemcomprising: a low pressure supply route comprising a low pressurehydraulic pump that generates a low hydraulic pressure using a fluidthat is stored at a low pressure oil pan and that supplies a generatedlow hydraulic pressure directly to a gear lubrication device and aclutch cooling/lubrication device, and a cooler that cools a portion ofthe low hydraulic pressure that is supplied from the low pressurehydraulic pump and that supplies the portion of the low hydraulicpressure to the gear lubrication device or the clutchcooling/lubrication device; and a high pressure supply route comprisinga high pressure hydraulic pump that generates a high hydraulic pressureusing a fluid that is stored at a high pressure oil pan and thatsupplies a generated high hydraulic pressure, a clutch control deviceincluding first and second clutch pressure control solenoid valves thatsupply a portion of the high hydraulic pressure to first and secondclutches, and a gear control device including a gear actuator pressurecontrol solenoid valve that is configured to control other portion ofthe high hydraulic pressure and that supplies a controlled hydraulicpressure to a gear actuator, wherein the low pressure supply route andthe high pressure supply route each are formed with an independentclosed circuit, wherein the low hydraulic pressure is a hydraulicpressure lower than a predetermined hydraulic pressure and the highhydraulic pressure is a hydraulic pressure equal to or higher than thepredetermined hydraulic pressure, wherein the low pressure supply routefurther comprises a switching valve regulating a flow rate supplied fromthe low pressure hydraulic pump and supplying a regulated flow rateselectively to the gear lubrication device and the clutchcooling/lubrication device, and wherein the low pressure supply routefurther comprises an ejection flow channel that is formed between thelow pressure hydraulic pump and the switching valve, a firstdistribution flow channel that detours the switching valve and connectsthe low pressure hydraulic pump with the gear lubrication device asecond distribution flow channel that detours the switching valve andconnects the low pressure hydraulic pump with the clutchcooling/lubrication device, a first bypass flow channel that is formedbetween the switching valve and the gear lubrication device, and asecond bypass flow channel that is formed between the switching valveand the clutch cooling/lubrication device.
 2. The hydraulic pressuresupply system of claim 1, wherein the gear control device furtherincludes a gear actuator flow rate control solenoid valve that ispositioned between the gear actuator pressure control solenoid valve andthe gear actuator and that regulates a flow rate of a hydraulic pressurethat is supplied from the gear actuator pressure control solenoid valveto supply the flow rate to the gear actuator.
 3. The hydraulic pressuresupply system of claim 1, wherein the low pressure supply route furthercomprises a low pressure filter that is disposed between the lowpressure oil pan and the low pressure hydraulic pump.
 4. The hydraulicpressure supply system of claim 1, wherein the low pressure supply routefurther comprises a clutch protection relief valve and a first orificethat are disposed between upstream and downstream of the cooler.
 5. Thehydraulic pressure supply system of claim 4, wherein the clutchprotection relief valve is formed with a one-way valve that supplies ahydraulic pressure only from the upstream to the downstream of thecooler.
 6. The hydraulic pressure supply system of claim 1, wherein thelow pressure supply route further comprises a branch flow channel thatconnects the ejection flow channel and the first distribution flowchannel, and the cooler is positioned on the branch flow channel.
 7. Thehydraulic pressure supply system of claim 1, wherein the low pressuresupply route further includes a second orifice that is positioned on thefirst distribution flow channel between the cooler and the gearlubrication device and a third orifice that is positioned on the seconddistribution flow channel.
 8. The hydraulic pressure supply system ofclaim 1, wherein the clutch control device further includes a fail-safesolenoid valve that is positioned at an upstream side of the first andsecond clutch pressure control solenoid valves.
 9. A hydraulic pressuresupply system of a dual clutch transmission for a vehicle, the hydraulicpressure supply system comprising: a low pressure supply routecomprising a low pressure hydraulic pump that generates a low hydraulicpressure using a fluid that is stored at a low pressure oil pan and thatsupplies a generated low hydraulic pressure directly to a gearlubrication device and a clutch cooling/lubrication device, and a coolerthat cools a portion of the low hydraulic pressure that is supplied fromthe low pressure hydraulic pump and that supplies the portion of the lowhydraulic pressure to the near lubrication device or the clutchcooling/lubrication device; and a high pressure supply route comprisinga high pressure hydraulic pump that generates a high hydraulic pressureusing a fluid that is stored at a high pressure oil pan and thatsupplies a generated high hydraulic pressure, a clutch control deviceincluding first and second clutch pressure control solenoid valves thatsupply a portion of the high hydraulic pressure to first and secondclutches, and a gear control device including a gear actuator pressurecontrol solenoid valve that is configured to control other portion ofthe high hydraulic pressure and that supplies a controlled hydraulicpressure to a gear actuator, wherein the low pressure supply route andthe high pressure supply route each are formed with an independentclosed circuit, wherein the low hydraulic pressure is a hydraulicpressure lower than a predetermined hydraulic pressure and the highhydraulic pressure is a hydraulic pressure equal to or higher than thepredetermined hydraulic pressure, and wherein the high pressure supplyroute further comprises a first high pressure filter that is positionedat an upstream side of the high pressure hydraulic pump, a second highpressure filter that is disposed at a downstream side of the highpressure hydraulic pump, and an one-way valve that is disposed in seriesto the second high pressure filter at the downstream side of the highpressure hydraulic pump.
 10. The hydraulic pressure supply system ofclaim 9, wherein the first high pressure filter is formed with a meshfilter, and the second high pressure filter is formed with a pressurefilter.
 11. A hydraulic pressure supply system of a dual clutchtransmission for a vehicle, the hydraulic pressure supply systemcomprising: a low pressure supply route comprising a low pressurehydraulic pump that generates a low hydraulic pressure using a fluidthat is stored at a low pressure oil pan and that supplies a generatedlow hydraulic pressure directly to a gear lubrication device and aclutch cooling/lubrication device, and a cooler that cools a portion ofthe low hydraulic pressure that is supplied from the low pressurehydraulic pump and that supplies the portion of the low hydraulicpressure to the gear lubrication device or the clutchcooling/lubrication device; and a high pressure supply route comprisinga high pressure hydraulic pump that generates a high hydraulic pressureusing a fluid that is stored at a high pressure oil pan and thatsupplies a generated high hydraulic pressure, a clutch control deviceincluding first and second clutch pressure control solenoid valves thatsupply a portion of the high hydraulic pressure to first and secondclutches, and a gear control device including a gear actuator pressurecontrol solenoid valve that is configured to control other portion ofthe high hydraulic pressure and that supplies a controlled hydraulicmeasure to a gear actuator, wherein the low pressure supply route andthe high pressure supply route each are formed with an independentclosed circuit, wherein the low hydraulic pressure is a hydraulicpressure lower than a predetermined hydraulic pressure and the highhydraulic Pressure is a hydraulic pressure equal to or higher than theredetermined hydraulic pressure, and wherein the high pressure supplyroute further includes a supply flow channel that connects the highpressure hydraulic pump, the clutch control device, and the gear controldevice, and at the supply flow channel, an accumulator that temporarilystores hydraulic pressure supplied from the high pressure hydraulic pumpand supplies a stored hydraulic pressure to the clutch control device, aline relief valve that maintains a hydraulic pressure on the supply flowchannel to a predetermined pressure or less, and a pressure sensor thatdetects a hydraulic pressure on the supply flow channel are positioned.